Method of manufacturing light-emitting module

ABSTRACT

A method of manufacturing a light-emitting module according includes providing an intermediate structure, the intermediate structure including a board, and a plurality of light sources, and forming first and second wirings on an upper surface of the intermediate structure. The first wiring includes first extending portions and first connecting portions. The second wiring includes second extending portions and second connecting portions. The forming of the first and second wirings includes forming the first extending portions and the first connecting portions and the second extending portions, forming an insulating member covering at least the first connecting portions while at least a portion of each of the second extending portions is exposed from the insulating member, and forming the second connecting portions on or above a part of the insulating member positioned on or above the first connecting portions of the first wiring.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2020-015089, filed on Jan. 31, 2020 and Japanese Patent Application No.2021-006953, filed on Jan. 20, 2021, the disclosures of which are herebyincorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates to a method of manufacturing alight-emitting module.

Light-emitting devices including light-emitting elements such aslight-emitting diodes are widely used for backlights for liquid-crystaldisplays or various light sources for displays or the like. As such alight-emitting device, a structure in which a light-emitting element isplaced on a substrate provided with wiring has been proposed. Forexample, Japanese Patent Application Publication No. 2002-329896discloses a light-emitting device in which electrodes on the lowersurface of a light-emitting element are connected to wiring on the uppersurface of a substrate.

SUMMARY

Further size reduction of light-emitting devices has been demanded inrecent years. In order to reduce the size of a light-emitting device, alight-emitting element and wiring are required to be precisely arranged.

The present disclosure may provide a method of manufacturing alight-emitting module for which size reduction is possible.

A method of manufacturing a light-emitting module according to anembodiment of the present disclosure includes providing an intermediatestructure, the intermediate structure including a board, and a pluralityof light sources arranged on an upper surface of the board along a firstdirection and a second direction different from the first direction, thelight sources each including a first electrode and a second electrodeexposed from an upper side of a corresponding one of the light sources;and forming a first wiring and a second wiring on an upper surface ofthe intermediate structure. The first wiring includes a plurality offirst extending portions each extending from the first electrode of acorresponding one of the light sources and extending at least partiallyin the second direction, and a plurality of first connecting portionseach extending in the first direction and electrically connecting two ormore of the first extending portions. The second wiring includes aplurality of second extending portions each extending from the secondelectrode of a corresponding one of the light sources and extending atleast partially in the first direction, and a plurality of secondconnecting portions each extending in the second direction andelectrically connecting two or more of the second extending portions.The forming of the first wiring and the second wiring includes formingthe first extending portions and the first connecting portions of thefirst wiring and the second extending portions of the second wiring,forming an insulating member covering at least the first connectingportions of the first wiring while at least a portion of each of thesecond extending portions of the second wiring is exposed from theinsulating member, and forming the second connecting portions of thesecond wiring on or above a part of the insulating member positioned onor above the first connecting portions of the first wiring.

According to a method of manufacturing a light-emitting module of anembodiment of the present disclosure, a light-emitting module for whichsize reduction is possible can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic top view of a light-emitting module according toan embodiment.

FIG. 2 is a schematic enlarged top view of light sources and theirvicinities in FIG. 1.

FIG. 3 is a schematic enlarged top view of the light sources and theirvicinities in FIG. 1.

FIG. 4 is a schematic further enlarged top view of a light source andits vicinity in FIG. 3.

FIG. 5A is a schematic cross-sectional view of the light-emitting moduleaccording to the embodiment taken along the line V-V′ of FIG. 1.

FIG. 5B is a schematic cross-sectional view of the light-emitting moduleaccording to the embodiment taken along the line VB-VB′ of FIG. 1.

FIG. 6 is a schematic cross-sectional view of a light source in thelight-emitting module according to the embodiment.

FIG. 7 is a schematic cross-sectional view showing a step of a method ofmanufacturing the light-emitting module according to the embodiment.

FIG. 8 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 9 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 10 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 11 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 12 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 13 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 14 is a schematic top view showing a step of the method ofmanufacturing the light-emitting module according to the embodiment.

FIG. 15 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 16 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 17 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 18 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 19 is a schematic cross-sectional view showing a step of the methodof manufacturing the light-emitting module according to the embodiment.

FIG. 20 is a schematic top view showing a step of the method ofmanufacturing the light-emitting module according to the embodiment.

FIG. 21 is a schematic cross-sectional view of another example of alight source in the light-emitting module according to the embodiment.

DETAILED DESCRIPTION

An embodiment of the present invention will be described below withreference to the accompanying drawings. The embodiment described belowis intended to embody the technical idea of the present invention and isnot intended to limit the present invention to the embodiment belowunless specifically stated otherwise. The sizes, positionalrelationships, and the like of members shown in the drawings can beexaggerated for clarity of descriptions.

The present invention will be described below in detail on the basis ofthe accompanying drawings. The descriptions below include termsindicating specific directions or positions (for example, “up”, “upper”,“down”, “lower” and other terms inclusive of these terms) asappropriate. Use of these terms is, however, intended to facilitateunderstanding of the present invention with reference to the drawings,and the meanings of these terms do not limit the technical scope of thepresent invention. A portion with the same reference numeral in aplurality of drawings represents the same or equivalent portion ormember.

In the embodiment described below, an example of a light-emitting moduleis described to give concrete form to the technical idea of the presentinvention, and the present invention is not limited to the descriptionbelow. Unless otherwise specified, sizes, materials, shapes, andrelative positions of constituent components described below are notintended to limit the scope of the present invention thereto, but ratherare described as examples. Constitutions described in one embodiment maybe applicable to other embodiments or examples. Sizes or positionalrelationships of components illustrated in the drawings may beexaggerated in order to clarify the descriptions.

FIG. 1 is a schematic top view of a light-emitting module obtained by amanufacturing method according to the present embodiment. FIG. 2 andFIG. 3 are schematic enlarged views of light sources 20 and theirvicinities in FIG. 1. FIGS.5A and 5B are schematic cross-sectional viewsof the light-emitting module obtained by the manufacturing methodaccording to the present embodiment. FIG. 6 is a schematiccross-sectional view of a light source in the light-emitting moduleaccording to the present embodiment.

The light-emitting module includes a board 10, a plurality of lightsources disposed on the upper surface of the board 10, a covering layer30 disposed around the light sources, an insulating member 40, firstwiring 50, and second wiring 60. The light sources 20 aretwo-dimensionally arranged in a plurality of rows and a plurality ofcolumns. The arrangement of the light sources 20 is not limited to atwo-dimensional arrangement but can be any arrangement appropriatelydetermined such as a honeycomb arrangement.

In the example shown in FIG. 1 and FIG. 2, the light sources 20 arearranged along a first direction (“1st” in Figures) and a seconddirection (“2nd” in Figures) in a light-emitting module 100. In thepresent specification, the term “first direction” refers to a direction(lateral direction in FIG. 1) in which the rows of the light sources 20extend, and the term “second direction” refers to a direction (verticaldirection in FIG. 1) in which the columns of the light sources 20extend.

In the present example, each of the light sources 20 has a square shapein a top view. The length of each side of the square shape can be withinthe range of, for example, about 15 μm or more and about 1,000 μm orless. In the present example, the light-emitting module also has aquadrangular outer shape. The lengths of the quadrangular light-emittingmodule in the longitudinal and lateral directions are respectively, forexample, 8 cm and 6 cm. The number and shape of the light sources 20 inthe light-emitting module 100 can be appropriately determined, and theshape of the light-emitting module 100 can also be appropriatelydetermined.

Each of the light sources 20 has an electrode formation surface 20 c andan emission surface 20 a opposite to the electrode formation surface 20c. The electrode formation surface 20 c is provided with a pair ofpositive and negative electrodes, that is, a first electrode 23 a and asecond electrode 23 b, on the same surface. The light source 20 isdisposed directly or with a bonding member or the like therebetween suchthat the emission surface 20 a faces the upper surface of the board 10.

The light source 20 includes a light-emitting element 21. Alight-transmissive member 22 is disposed on an emission surface 21 a ofthe light-emitting element 21. The light-emitting element 21 is bondedto the light-transmissive member 22 with a light-transmissive adhesivemember 24. The light-transmissive member 22 covers the emission surface21 a of the light-emitting element 21 and extends outward of lateralsurfaces 21 b of the light-emitting element.

The lateral surfaces 21 b of the light-emitting element 21 are coveredwith a covering member 26. The covering member 26 constitutes a portionof the electrode formation surface 20 c of the light source 20. Thecovering member 26 is also disposed on an electrode formation surface ofthe light-emitting element 21 such that at least a portion of thesurface of each of the first electrode 23 a and the second electrode 23b of the light-emitting element 21 are exposed from the upper side ofthe light source 20.

The covering layer 30 covers lateral surfaces 20 b of the light source20. In the example shown in FIGS. 5A and 5B, the electrode formationsurface 20 c of the light source 20 is exposed from the covering layer30. The electrode formation surface 20 c of the light source 20 can becovered with the covering layer 30 except for the regions in which thefirst electrode 23 a and the second electrode 23 b are disposed.

The first wiring 50 is disposed over the light sources 20 and thecovering layer 30. The first wiring 50 includes first extending portions51 and first connecting portions 52. Each of the first extendingportions 51 is disposed for the first electrode 23 a of a correspondingone of the light sources 20 and extends from the first electrode 23 a inthe second direction. The first connecting portions 52 extend in thefirst direction and each electrically connect a plurality of firstextending portions 51. The first connecting portions 52 are providedwith external terminals 55. Each of the first connecting portions 52 isintegrally formed with the first extending portions 51 in thelight-emitting module.

The second wiring 60 is disposed over the light sources 20 and thecovering layer 30. The second wiring 60 includes second extendingportions 61 and second connecting portions 62. Each of the secondextending portions 61 is provided for the second electrode 23 b of acorresponding one of the light sources 20, and extends from the secondelectrode 23 b in the first direction. The length of the secondextending portion 61 in its extending direction is greater than thewidth of the second extending portion 61 in a direction perpendicular tothe extending direction in a top view. Making the second extendingportion 61 extending from the second electrode 23 b such that the secondextending portion 61 is elongated can facilitate alignment when eachsecond connecting portion 62 connected to a plurality of secondextending portions 61 is formed.

The insulating member 40 covers a plurality of first connecting portions52. In the example shown in FIGS. 5A and 5B, the insulating member 40 isdisposed over the light sources 20, the first wiring 50, the secondextending portions 61, and the covering layer 30. The insulating member40 has openings in each of which at least a portion of the secondextending portion 61 is exposed. The openings are located away from thesecond electrodes 23 b in a top view.

The second connecting portions 62 extend in the second direction, andeach electrically connect a plurality of second extending portions 61 atthe openings of the insulating member 40. The second connecting portions62 are provided with external terminals 55.

FIG. 4 is a schematic further enlarged top view of a light source 20 andits vicinity in FIG. 3. In FIG. 4, the first electrode 23 a and thesecond electrode 23 b are respectively located in portions on a lineconnecting diagonally opposite corners of the electrode formationsurface 20 c of the rectangular light source 20. In FIG. 4, the firstelectrode 23 a and the second electrode 23 b are right triangular andare separated from each other along a diagonal line of the electrodeformation surface 20 c of the rectangular light source 20. The firstextending portion 51 includes a first portion 51 a and a second portion51 b. The first portion 51 a extends from the first electrode 23 atoward the corner of the electrode formation surface 20 c which islocated opposite side from the second electrode 23 b, in a top view. Thesecond portion 51 b extends in the second direction, and connects thefirst portion 51 a to the first connecting portion 52. A length 51 aL ofthe first portion 51 a in its elongated direction is greater than awidth 51 aW of the first portion 51 a in a direction perpendicular tothe elongated direction in a top view. The second extending portion 61includes a third portion 61 c extending from the second electrode 23 btoward the corner of the electrode formation surface 20 c which islocated opposite side from the first electrode 23 a, in a top view. Thefourth portion 61 d extends in the first direction, and connects thethird portion 61 c to the second connecting portion 62. A length 61 cLof the third portion 61 c in its elongated direction is greater than awidth 61 cW of the third portion 61 c in a direction perpendicular tothe elongated direction in a top view. This structure allows foreffectively reducing a short circuit between the first extending portion51 and the second extending portion 61. The shapes of the firstelectrode 23 a and the second electrode 23 b in a top view are notlimited to triangular but can be, for example, rectangular.

The method of manufacturing the light-emitting module will be describedin detail referring to schematic cross-sectional views of FIG. 7 to FIG.13 and FIG. 15 to FIG. 19.

Step of Providing Intermediate Structure

An intermediate structure 90 in which a plurality of light sources 20and the covering layer 30 are disposed on the board 10 is provided.

As shown in FIG. 7, the light sources 20 are disposed on the board 10.The light sources 20 are arranged on the upper surface of the board 10along the first direction and the second direction. The light sources 20are disposed with their electrode formation surfaces 20 c facing up andtheir emission surfaces 20 a facing down. In the light-emitting module,the light sources 20 are arranged at predetermined intervals. The lightsources 20 can be disposed without intervals such that lateral surfacesof the light sources 20 are brought into contact with each other. Inthis case, a step of forming the covering layer 30 described below canbe omitted to dispose the first wiring 50 and the second wiring 60 onthe light sources 20.

The board 10 is such a board that the light sources 20 can be placed.The shape of the board 10 is not limited to particular shapes, but itsupper surface is preferably flat. The light sources 20 are bonded to theboard 10 with light-transmissive bonding members. Examples of thebonding members include epoxy resins.

Subsequently, the covering layer 30 is formed around the light sources20 on the board 10. The covering layer 30 is disposed by applying thematerial of the covering layer 30 over the board. The method of applyingthe cover layer 30 is not limited to particular methods, and examplesthereof include spin coating using a spin coater and discharging using adispenser. The covering layer 30 can be formed of, for example, apolyimide or an epoxy resin.

The covering layer 30 can be formed so as to cover the board 10 and thelight sources 20 with the material of the covering layer 30, and thenpartially removing the covering layer 30 until the first electrodes 23 aand the second electrodes 23 b of the light sources 20 are exposed.

Step of Forming Wiring

Wiring including the first wiring 50 and the second wiring 60 is formedon the upper surface of the resulting intermediate structure. A step offorming wiring includes a step of forming the first wiring 50 and thesecond extending portions 61, a step of forming the insulating member40, and a step of forming the second wiring by forming the secondconnecting portions 62.

Step of Forming First Wiring 50 and Second Extending Portions 61

The first wiring 50 including the first extending portions 51 and thefirst connecting portions 52, and the second extending portions 61 thatare a portion of the second wiring 60, are first formed. The positionsof the first electrodes 23 a and the second electrodes 23 b of therespective light sources 20 are detected, and the first extendingportions 51 and the second extending portions 61 are formed so as torespectively correspond to the positions of the first electrodes 23 aand the second electrodes 23 b. The first wiring 50 and the secondextending portions 61 are formed by layering a first metal layer 71 anda second metal layer 72.

In the step of forming the first wiring 50 and the second extendingportions 61, the first metal layer 71 is formed by sputtering or thelike over substantially the entire upper surfaces of the light sources20 and the covering layer 30 as shown in FIG. 8. The first metal layer71 is used as a seed layer for formation of the second metal layer 72 byelectroplating in a step of forming the second metal layer 72 that is asubsequent step. Examples of the layered structure of the first metallayer 71 include Ti/Cu layered in this order from the board 10.

Subsequently, a resist 81 is formed on the first metal layer 71 as shownin FIG. 9. The resist 81 has openings corresponding to the firstextending portions 51, the first connecting portions 52, and the secondextending portions 61 in a top view. The resist 81 can be formed into adesired shape corresponding to the pre-detected positions of the firstelectrodes 23 a and the second electrodes 23 b by direct writing usingultraviolet laser light or the like.

Subsequently, the second metal layer 72 is formed in the openings of theresist 81 by electroplating as shown in FIG. 10. The second metal layer72 is formed by plating growth in the openings of the resist using thefirst metal layer 71 as the seed layer, which is the current path, forelectroplating. Examples of the second metal layer 72 include Cu.

The resist is then removed to expose the first metal layer 71 as shownin FIG. 11. Subsequently, etching is performed to reduce the thicknessof the second metal layer 72 by partially removing the second metallayer 72 and to remove portions of the first metal layer 71 where thesecond metal layer 72 is not provided, as shown in FIG. 12. The firstwiring 50 and the second extending portions 61 formed by layering thefirst metal layer 71 and the second metal layer 72 are thus formed. Theetching can be either dry etching or wet etching.

In the case in which the light sources 20 each have a quadrangular shapein a top view as shown in FIG. 2, it is preferable that the pair of thefirst electrode 23 a and the second electrode 23 b are triangular in atop view and located diagonally opposite to each other on each lightsource 20. This structure can enlarge the pair of the first electrode 23a and the second electrode 23 b in the first direction and the seconddirection even in a small light source, so that sufficient areas forbonding to the pair of the first extending portion 51 and the secondextending portion 61 to be formed on the first electrode 23 a and thesecond electrode 23 b can be obtained.

Step of Forming Insulating Member 40

Subsequently, the insulating member 40 is formed on the first wiring 50and the second extending portions 61 as shown in FIG. 13. The insulatingmember 40 is disposed at least over the first connecting portions 52 andbetween the first connecting portions 52 and the second connectingportions 62 described below. In the example shown in FIG. 13, theinsulating member 40 is formed over the first wiring 50 and the secondextending portions 61. After the insulating member 40 is formed, theinsulating member 40 is patterned by, for example, photolithography tocover the first wiring 50 and the second extending portions 61 and haveopenings 41 at positions overlapping with the second extending portions61 in a top view. FIG. 14 is a schematic enlarged view of a portion ofthe light-emitting module after the insulating member 40 is formed. Asshown in FIG. 14, the openings 41 of the insulating member 40 overlapwith the second extending portions 61, and the second extending portions61 are partially exposed at the positions of the openings 41. Theinsulating member 40 can be formed of, for example, a silicone or epoxyresin which are photosensitive. The insulating member 40 is formed by,for example, transfer molding, compression molding, potting, printing,or spraying to have such a thickness (such as about 2 μm to 500 μm) thatthe first wiring 50 and the second extending portions 61 are embeddedinside on the light sources 20 and the covering layer 30.

Step of Forming Second Connecting Portions 62

Subsequently, the second connecting portions 62 each of whichelectrically connect a plurality of second extending portions 61 areformed. The second connecting portions 62 are formed by layering a thirdmetal layer 73 and a fourth metal layer 74.

In the step of forming the second connecting portions 62, the thirdmetal layer 73 is first formed by sputtering or the like oversubstantially the entire upper surfaces of the insulating member 40 andthe second extending portions 61 exposed in the openings as shown inFIG. 15. The third metal layer 73 is used as a seed layer for formationof the fourth metal layer 74 by electroplating in a step of forming thefourth metal layer 74, which is a subsequent step. Similarly to thematerials of the first metal layer 71, examples of the layered structureof the third metal layer 73 include Ti/Cu layered in this order from theboard 10.

Subsequently, a resist 83 is formed on the third metal layer 73 as shownin FIG. 16. The resist 83 has openings 84 corresponding to the secondconnecting portions 62.

Subsequently, the fourth metal layer 74 is formed in the openings 84 ofthe resist 83 by electroplating as shown in FIG. 17. The fourth metallayer 74 is formed by plating growth in the openings of the resist usingthe third metal layer 73 as the seed layer, which is the current path,for electroplating. Similarly to the second metal layer 72, examples ofthe material of the fourth metal layer 74 include Cu.

The resist is then removed to expose the third metal layer 73 as shownin FIG. 18. Further, etching is performed to reduce the thickness of thefourth metal layer 74 by partially removing the fourth metal layer 74and to remove portions of the third metal layer 73 where the fourthmetal layer 74 is not provided. The second connecting portions 62 madeby layering third metal layer 73 and the fourth metal layer 74 are thusformed as shown in FIG. 19. The second connecting portions 62 extend inthe second direction and are electrically connected to the secondextending portions 61 aligned in the second direction at the positionsof the openings 41 through the openings 41 as shown in FIG. 20. Thisstructure can allow the second electrodes 23 b of the light sources 20aligned in the second direction to be electrically connected to eachother with the second connecting portions 62. In the step of forming thesecond connecting portions 62, the external terminals 55 can be formedat the same time.

The light-emitting module 100 having the structure shown in FIGS. 5A and5B can be obtained in this way. The first extending portions 51 of thefirst wiring 50 and the second extending portions 61 of the secondwiring 60 respectively correspond to the positions of the firstelectrodes 23 a and the second electrodes 23 b of the light sources 20,so that the first electrodes 23 a and the second electrodes 23 b of thelight sources 20 can be securely connected to the first wiring 50 andthe second wiring 60, respectively. For example, even if a light source20 is misaligned in a step of disposing the light sources 20 or the likeas shown in FIG. 3, the first extending portion 51 and the secondextending portion 61 can be precisely arranged with respect to the firstelectrode 23 a and the second electrode 23 b by modifying the angle ofthe first portion 51 a of the first extending portion 51, the angle ofthe third portion 61 c of the second extending portion 61, the length ofthe second portion 51 b of the first extending portion 51, and/or thelength of the fourth portion 61 d of the second extending portion 61.With this structure, poor connections caused by misalignment of thefirst electrode 23 a and the second electrode 23 b of the light source20 to the first wiring 50 and the second wiring 60 can be reducedcompared with the case in which the electrodes of the light source 20are disposed to face wiring formed on the board. The first wiring 50 andthe second extending portions 61 are formed in the same step, so thatthe manufacturing steps can be simplified. The first wiring 50 does notoverlap with the second extending portions 61, so that thelight-emitting module with the reduced thickness can be obtained. Thesecond extending portions 61 provided for the electrodes of the lightsources is formed in the different step from the second connectingportions 62, to thereby efficiently forming the second wiring.

Each component of the light-emitting module will be described below.

Board 10

The shape of the board 10 is not limited to particular shapes as long asthe light sources 20 and the covering layer 30 can be disposed on theupper surface of the board 10, but the upper surface is preferably flat.An insulating board can be used as the board 10. The board 10 ispreferably light transmissive but is not limited thereto. For example,glass or ceramic is preferably used for the board 10. The board 10 canbe flexible. The thickness of the board 10 is not limited to particularvalues but is, for example, about 0.1 mm to 1 mm.

In the example shown in FIGS. 5A and 5B, the upper surface of the board10 is flat. The upper surface of the board 10 may not necessarily beflat. The upper surface can have recesses respectively corresponding tothe light sources 20, and the light sources 20 can be disposed in therecesses.

Covering Layer 30

The covering layer 30 covers lateral surfaces of the light sources 20. Alight-reflective material can be used for the covering layer 30. Thelight-reflective covering layer 30 preferably has a reflectance of 60%or more, more preferably 90% or more, with respect to light emitted fromthe light sources 20. The material of the light-reflective coveringlayer 30 can be resin containing a white pigment or the like. Inparticular, a silicone resin containing titanium oxide as alight-reflective material (or a light-scattering material) ispreferable. Using an inexpensive material such as titanium oxide as amaterial that is used in a relatively large amount to cover a surface ofthe board 10 allows the light-emitting module to be inexpensive. Thecovering layer 30 can be formed of a light-transmissive material such asresin not containing a white pigment or the like.

As the base material of the resin material constituting the coveringlayer 30, a silicone resin, a phenolic resin, an epoxy resin, a BTresin, polyphthalamide (PPA), or the like can be used. As thelight-reflective material, metal particles or particles of an inorganicor organic material having a refractive index higher than the refractiveindex of the base material can be used. Examples of the light-reflectivematerial include particles of titanium dioxide, silicon oxide, zirconiumdioxide, potassium titanate, aluminum oxide, aluminum nitride, boronnitride, mullite, niobium oxide, or barium sulfate and particles ofrare-earth oxides such as yttrium oxide and gadolinium oxide.

First Wiring 50 and Second Wiring 60

The first wiring 50 and the second wiring 60 are electrically connectedto the first electrodes 23 a and the second electrodes 23 b of the lightsources 20 respectively. With the first wiring 50 and the second wiring60, for example, a plurality of light sources 20 can be electricallyconnected to each other, and a circuit required for local dimming or thelike can be easily formed.

The material of the first wiring 50 and the second wiring 60 preferablyhas a low electrical resistance, and examples of the material include amaterial containing at least one selected from the group consisting ofCu, Au, and Al. Among these materials, Cu is preferable. The thicknessesof the first wiring 50 and the second wiring 60 are not limited toparticular values but are, for example, about 10 nm to 100 μm.

Light Source 20

In the example shown in FIG. 6, the light source includes thelight-transmissive member 22, the light-transmissive adhesive member 24,and the covering member 26 in addition to the light-emitting element 21.The light source 20 can be configured as the light-emitting element 21itself without including the light-transmissive member 22, thelight-transmissive adhesive member 24, and the covering member 26. Thethickness of the light source 20 is not limited to particular values butis, for example, about 100 μm to 1 mm.

Light-Emitting Element 21

The pair of electrodes are disposed on the same surface of thelight-emitting element 21. A known semiconductor light-emitting elementformed of a nitride semiconductor or the like can be used as thelight-emitting element 21. The light-emitting element 21 that emitslight having appropriately selected wavelength can be used to obtain adesired emission color.

Light-emitting diodes with various emission wavelengths can be used forthe light-emitting element 21. A phosphor described below can becombined to obtain a desired emission color. In particular, in order toobtain emission of white light, it is preferable to combine a nitridesemiconductor light-emitting element that emits blue light with aphosphor that absorbs the blue light to emit yellow, green, or redlight.

Light-Transmissive Member 22

The light-transmissive member 22 is disposed on the emission surface 21a of the light-emitting element 21. Transparent resin or glass can beused for the light-transmissive member 22. A silicone resin or the likeis preferably used as the transparent resin in view of durability,moldability, and the like.

The light-transmissive member 22 in the light source 20 can cover theupper surface 21 a and the lateral surfaces 21 b of the light-emittingelement 21 as shown in FIG. 21.

The light-transmissive member 22 can contain a wavelength conversionmember. The wavelength conversion member contains a phosphor that canabsorb light emitted from the light-emitting element 21 to emit lightwith another wavelength. Accordingly, the light-emitting module 100 canemit light with a mixed color, such as white light, resulting incombination of light emitted from the light-emitting element 21 andlight being subjected to wavelength conversion by the wavelengthconversion member, to the outside. The color of the emitted light can beappropriately adjusted by selecting the type of the light-emittingelement 21 and the type of the phosphor. The phosphor is excited bylight emitted from the light-emitting element 21 and emits light with awavelength different from the wavelength of the light emitted from thelight-emitting element 21. For example, a YAG phosphor, a β-SiAlONphosphor, a fluoride phosphor such as a KSF phosphor and an MGFphosphor, or a nitride phosphor such as a CASN phosphor can be used asthe phosphor. The light-transmissive member 22 can contain a pluralityof types of phosphors. A plurality of layers containing the phosphorscan be layered.

A wavelength conversion sheet can be disposed on the upper or lowersurface of the light-emitting module 100. The wavelength conversionsheet is typically a resin sheet in which phosphor particles aredispersed. Use of such a wavelength conversion sheet allows the phosphorto be uniformly disposed on the upper or lower surface of thelight-emitting module 100. In such a structure, the light-transmissivemember 22 is not required to contain a phosphor or the like.

What is claimed is:
 1. A method of manufacturing a light-emitting modulecomprising: providing an intermediate structure, the intermediatestructure including a board, and a plurality of light sources arrangedon an upper surface of the board along a first direction and a seconddirection different from the first direction, the light sources eachincluding a first electrode and a second electrode exposed from an upperside of a corresponding one of the light sources; and forming a firstwiring and a second wiring on an upper surface of the intermediatestructure, wherein the first wiring includes a plurality of firstextending portions each extending from the first electrode of acorresponding one of the light sources and extending at least partiallyin the second direction, and a plurality of first connecting portionseach extending in the first direction and electrically connecting two ormore of the first extending portions, the second wiring includes aplurality of second extending portions each extending from the secondelectrode of a corresponding one of the light sources and extending atleast partially in the first direction, and a plurality of secondconnecting portions each extending in the second direction andelectrically connecting two or more of the second extending portions,and the forming of the first wiring and the second wiring includesforming the first extending portions and the first connecting portionsof the first wiring and the second extending portions of the secondwiring, forming an insulating member covering at least the firstconnecting portions of the first wiring while at least a portion of eachof the second extending portions of the second wiring is exposed fromthe insulating member, and forming the second connecting portions of thesecond wiring on or above a part of the insulating member positioned onor above the first connecting portions of the first wiring.
 2. Themethod of manufacturing a light-emitting module according to claim 1,wherein the forming of the first wiring and the second wiring includesforming the first extending portions so that a length of each of thefirst extending portions in an elongated direction is greater than awidth of the first extending portion in a direction perpendicular to theelongated direction in a top view.
 3. The method of manufacturing alight-emitting module according to claim 1, wherein the forming of thefirst wiring and the second wiring includes forming the second extendingportions so that a length of each of the second extending portions in anelongated direction is greater than a width of the second extendingportion in a direction perpendicular to the elongated direction in a topview.
 4. The method of manufacturing a light-emitting module accordingto claim 1, wherein the forming of the first wiring and the secondwiring includes forming each of the first extending portions to includea first portion extending from the first electrode of the correspondingone of the light sources in a direction opposite to the second electrodeof the corresponding one of the light sources in a top view, and asecond portion extending in the second direction and connecting thefirst portion to a corresponding one of the first connecting portions,and the forming of the first wiring and the second wiring includesforming each of the second extending portions to include a third portionextending from the second electrode of the corresponding one of thelight sources in a direction opposite to the first electrode of thecorresponding one of the light sources in a top view, and a fourthportion extending in the first direction and connecting the thirdportion to a corresponding one of the second connecting portions.
 5. Themethod of manufacturing a light-emitting module according to claim 1,wherein the forming of the first wiring and the second wiring includesforming the first extending portions integrally with a corresponding oneof the first connecting portions.
 6. The method of manufacturing alight-emitting module according to claim 1, wherein the forming of thefirst wiring and the second wiring includes forming the first connectingportions, the first extending portions, and the second connectingportions by plating.
 7. The method of manufacturing a light-emittingmodule according to claim 1, wherein the providing of the intermediatestructure includes providing the intermediate structure including acovering layer disposed over the board and covering peripheries of thelight sources.